If America’s next president isn’t a lame duck, he needs to act like one.

President Barack Obama will be a lame duck if he is re-elected. Four more years and done. He can’t run again. That might be the single most compelling reason to re-elect Obama.

In his Cincinnati speech last week, Obama seemed to recognize that the atmosphere in Washington might change after the election if he wins.

“If I’m elected ... I actually think that a lot of Republicans, since this will be my last election, they will not be as interested in just beating me, and maybe they’ll be more interested in moving the country forward.”

In the same respect, the best argument for electing Republican Mitt Romney to replace Obama might be that he could have the courage to act like a lame duck — at least that’s what one of his top running mate prospects believes.

Speaking about Romney in an interview late last month with Reuters, Sen. Rob Portman of Ohio said, “I think he’d be willing to risk being a one-term president in order to make the tough decisions that are going to be required.”

At this juncture, the nation needs a president who doesn’t have to worry about re-election, or doesn’t care if he is re-elected. Being a lame duck, or acting like one, might be the only way the next president can do what has to be done. And doing that — raising taxes and cutting programs — would make him so unpopular that another term might be out of the question anyway.

I asked Robert L. Bixby, executive director of the Concord Coalition, a nonprofit and nonpartisan organization devoted to responsible fiscal policy, if he agreed that voters would be best served by electing a president who is unconcerned about being thrown out of office.

“I don’t know that voters would actually have that in their minds when they go to the polls, but I think a lot of political scientists might,” Bixby said. “There certainly is a political rationale for a term-limited president to make very hard choices.”

We are overdue on electing politicians willing to make hard choices. For too long, those choices have been recklessly deferred, putting our nation in fiscal peril, risking the well-being of future generations.

After the election, immediate action will be needed to avert a budget crisis. Without it, $600 billion worth of tax increases and spending cuts automatically will take effect in January, the result of last summer’s debt-limit showdown. Letting this happen, Federal Reserve Chairman Ben Bernanke warned last week, could throw the economy back into recession and cost 1.25 million jobs in 2013, including an estimated 40,000 in Ohio.

Beyond the short-term crisis is a long-haul imperative to get control of $1 trillion annual budget deficits and a national debt of $15 trillion. In 2013, the debt will exceed 70 percent of the country’s gross domestic product. Then there are the tens of trillions of dollars in unfunded obligations, primarily to Social Security and Medicare benefits.

Intellectually, Republicans know that tax increases and Democrats know that entitlement cuts are necessary, along with a total revamping of the tax code that, if done honestly and effectively, will gore sacred cows.

“There is a growing recognition of the magnitude of the problem and that something has to be done, but there is nowhere near the resolve to do anything about it,” Bixby said. “That leads to a very frustrating situation. It’s like a bunch of doctors standing around and watching a patient dying and arguing with each other over the right remedy.”

We voters are to blame. We don’t want to confront the hard choices, so we’re getting the cowardly candidates and vacuous campaigns we deserve.

“The public certainly is disgusted and alarmed — I think justifiably — about the deficit and frustrated with the politicians’ lack of will to do anything about it,” Bixby said. “But the public is conflicted on these things, as well, because if you look at any poll, people don’t want to see their taxes raised or their entitlements cut.”

And because we tend to punish any politician who advocates either, it is best we elect a lame duck, or at least a president who doesn’t care if he is one.